HP fic: Rematch [Severus/Sirius, adult]
Title: RematchAuthor: celandinebFandom: HPPairing: Severus/SiriusRating: adultLength: 3525Warnings: anal, rimming, blowjobsSummary: Severus is more than willing to have the rematch that Black suggested.Note: For daily_deviant's sixth birthday in March 2012, I opted to write a sequel to one of my Kinky Kristmas pieces from last December, "At Practice"... so this one's for r_grayjoy!

When Black challenged him under the Quidditch stand that January morning, Severus didn't have to think hard to decide to take him up on it. Most of him loathed the bullying bastard, but his prick had long acknowledged Black to be the best-looking wizard of their year -- or the two years before or behind them, for that matter. It was a win-win situation for Severus. Either he would beat Black, which would be extremely gratifying, or he'd get to suck him off after coming himself, which he would also enjoy.

He didn't play to lose. Timing an orgasm had never been his strong suit; mostly it was best, in Severus's experience, to come quickly. He accepted his loss with good grace and gave all his attention to sucking off Black as requested. Black's control was quite admirable. Severus half-expected him to come in Severus's mouth, but he didn't, and the distance that he shot his load was impressive.

Privately Severus was more than willing to have the rematch Black suggested, but he thought it better not to appear too eager. He waited more than a fortnight, until the day after the next Quidditch match. By mid-afternoon he had finished all of his assigned homework. Normally he would have done some N.E.W.T. revision, but instead decided to see if he could catch Black's attention.

Ever since their encounter, Severus had been wanking to thoughts of Black. He wondered if Black liked to take it up the arse... or if he ever had. Severus had. It was more or less a rite of passage amongst the Slytherin boys, one they were careful to keep from their Head of House although as a former Slytherin himself he doubtless knew about it. At any rate Severus had been initiated by in his second year by Lucius Malfoy, who had sufficient skill that Severus had not found it too unpleasant. Nevertheless on the whole he preferred to top than to bottom. He also wasn't sure that he would trust Black as a top. Of course, Black might feel the same way about him, in which case Severus would be willing to compromise by sticking with hand jobs or blow jobs, whichever Black might prefer. Thinking about having Black suck him off was almost as satisfying as thinking of Black pinned beneath him.

He found Black sweet-talking Madam Pince into letting him into the Restricted Section of the library. Severus himself had standing authorisation to access those books, thanks to a note that Slughorn had written for him at the beginning of the year, to enable him to do advanced research in Potions. As soon as Madam Pince had gone, Severus followed Black into the stacks. "Fifteen minutes from now, in the Charms classroom," Severus said quietly.

Black started to nod, then shook his head instead. "Not a classroom. Anyone could come in, and if we locked the door it would only make them more suspicious. I know a place. Meet me on the seventh floor, by that tapestry of Barnabas the Barmy."

"Right." Severus spotted a volume called Moste Potente Potions on the shelf, and grabbed it. He would take it down to his own room before going up to meet Black, letting the other boy leave directly from the library in a few minutes' time.

Severus was cautious as he approached the hallway Black had named. He thought that Black was eager enough for this that he wouldn't play any tricks, but long experience had taught him not to trust the Gryffindor. As far as he could tell, however, Black was alone, glancing nervously about.

"Finally." Black's voice was sharp. "Now, walk up and down with me three times, thinking about how much we need a place together in private, and why."

Severus raised his eyebrows, but complied with Black's request. To his astonishment, on their third pass a door had appeared in the stone wall where there had been nothing before. Black grinned and opened it. "Hurry, go on in."

The room was furnished with a large bed. The table nearby held pitchers of pumpkin juice and Butterbeer, platters of cakes and biscuits, and, somewhat incongruously, what Severus recognised as a bottle of lubricant, assorted anal plugs, and various other toys.

"Amazing," he breathed. "What is this place?"

"A safe place. It's here when you need it, that's all I know."

"We're here for that rematch you suggested," said Severus.

"Yeah. I'm not convinced we measured accurately last time, to start with, so I came up with something better." Black held up what looked like a piece of string. "When we're each ready, we can use this. I've charmed it to measure both length and diameter."

Severus nodded. "All right."

Unless there was some kind of cheat built into the charm, he wasn't worried. The boys in Slytherin House had come up with similar ways to compare sizes, and Severus had invariably won since his fourth year. He began unbuttoning his robes. Underneath them he was already bare; Black could not taunt him about his worn underthings today. He hadn't planned to strip completely, knowing that his body was not conventionally attractive, but Black was quick to pull off all his own clothes, and after that Severus felt he had no choice. At least the room was warm.

Severus had to admit that the charm that Black had put on the string was quite clever. Black went first. He placed one end of the string at the base of his erect prick, and the remainder inched its way up to the tip. When he touched the endpoint with his wand, a thin scarlet line appeared across the string to mark the measurement. Next the string wound itself around Black's prick and slid all the way down, then retreated slightly. Again Sirius used his wand to mark the measurement.

"It registers the thickest part," he explained, unwrapping the string and holding it out to Severus, who had been stroking himself as he watched. "Once it's checked the whole way down, it goes back to wherever was widest and stops there."

Severus nodded. "Do I need to cast some spell to mark the string, or will a touch of the wand do it?"

"Just touch it. The first two lines were red and orange, and the next two ought to be green and blue."

Having the string sliding its way along his cock was quite stimulating, Severus found. He was gratified to see that as before, he outdid Black in length by a full quarter of an inch, perhaps even closer to three-eighths. Thickness, however, proved to be another matter. There Black had the advantage, again of perhaps a quarter inch. Equal, then, or near enough; Severus was content with that.

"If the point is how good you are at sex, shouldn't it be how well you get the other person off?" Severus thought that was quite reasonable.

"But how can you measure that? Some people prefer to come quickly, others like to take it slow, and quality is subjective." Black was taking Severus's proposal seriously.

Severus pretended to think it over. "So it's subjective. Here's an idea. Have you ever been fucked in the arse?"

"Yeah." Black gave Severus a look that dared him to comment.

"All right, then. We can take turns doing it to each other today. I know where Slughorn keeps a stock of truth serum. I'll pinch some of it and later this week we each take a drop and say how good the other one was. Does that sound fair?"

"Who goes first today?" countered Black.

"You can choose." Severus didn't care much. "The only thing is, we can't touch each other's pricks or balls. It's about how well you do with your cock, not your fingers."

"Fair enough," said Black after a moment. "I'll do you first."

Severus nodded and put the tip of his wand to his arse to cast Lubricio. Not that he thought Black would try to fuck him dry -- that would be an almost guaranteed way for Black to lose -- rather that he didn't want to take the chance that Black might choose a lubrication charm with any extra-stimulating properties. "Do you want me to stand, kneel, or what?"

"Kneel. On the bed, or both our knees will be sore," Black said.

Severus got onto the bed and positioned himself on hands and knees. He heard the bedsprings creak as Black crawled up behind him.

Black's cock nudged against the back of Severus's bollocks before Black got it aimed better. He took it slowly, letting Severus's own breaths set the pace of his penetration, until he was fully inside. Once there he rocked gently, altering his angle with each thrust. Severus knew what Black must be trying to do, but he could not hold back a gasp when Black's prick stroked his prostate. Black stopped shifting then, and his strokes speeded up a little. His fingers wandered over Severus's arse, going so far as to stroke his perineum and caress the rim of his arsehole, though Black was careful to stick to the terms of their agreement and scrupulously avoided Severus's bollocks and cock.

He was good, Severus had to admit, and wondered with whom Black had had so much practice. Potter? Lupin? He doubted it would have been Pettigrew, both because he was unattractive and because he struck Severus as being entirely straight. Severus had never much cared for bottoming. Any pleasure he had was moderate at best, and partly due to his sense of pride at accommodating his partner and contributing to that person's gratification. In the unlikely event that he had further encounters with Black, however, he just might change his mind, Severus decided, letting himself take on Black's rhythm.

Lost in such thoughts, he was surprised and almost sorry when Black clutched at him and groaned in orgasm. When he then withdrew, he left Severus's arse gaping empty, wanting more.

"My turn," he said with as much confidence as possible. He had been careful in his wording when he gave the terms of their contest, and concealed a smirk as they exchanged places.

Like Severus, Black cast his own lubrication charm, but Severus quickly whispered a cleansing spell in addition. He knelt between Black's ankles and used his hands to part the other boy's arsecheeks, but instead of sliding his prick into Black's tempting aperture, he lowered his head and put his tongue there instead.

"Oi!" exclaimed Black. "That's not fair!"

"Neither of us excluded it," Severus lifted his face to point out. "We just said no touching pricks or bollocks. You used your fingers on my arse, and you could have used your mouth if you'd thought of it." He lowered his head again, ignoring Black's continued grumbling, but it was several minutes before his concentrated ministrations distracted Black sufficiently to shut him up.

Severus enjoyed rimming. Not as much as sucking cock, perhaps, but there was something about the intimacy of it, breaking taboos, that thrilled him even when he didn't much like his partner. Malfoy had been the first to teach him this, both giving and receiving, and that had been distinctly enjoyable. Later hazing experiences from Rookwood and Avery and several other older Slytherin boys had given him substantial practise in technique, all of which he put to use on Black now, teasing the puckered muscle wide open and slipping his tongue inside, until he heard Black's breath coming in short pants despite his recent orgasm.

Then at last Severus knelt up again and brought the head of his prick to Black's waiting arsehole, the slippery heat engulfing him. He, too, sought out the sweet spot that lay within, eliciting a strangled moan from Black's throat. Merlin, but it felt good to plunge again and again into Black's arse, to know that his bitterest foe lay open to him, writhing beneath him. Unless Black's previous partners had been more talented than Severus could believe, he thought smugly, he was certain to win once they took truth serum and compared their reactions.

The almost electric sensations were building now to their peak. Severus heard his own soft grunts rise to a keen as he pounded rapidly into Black's arse, though he retained enough control to be careful not to be so overenthusiastic as to cause discomfort and thereby undo all his earlier efforts to ensure that Black enjoyed it. His climax wrenched his spunk out in three pulses so intense that for a moment he could not see.

"So we meet again later this week to take the truth serum. Which of us should get that from Slughorn's supplies? I don't think he'll just give it away?" Black asked as Severus withdrew.

"I'll get it. Slughorn likes you," although Severus couldn't imagine why, except that the Blacks were an old, wealthy, and well-connected family, "so you can distract him during class and I'll take the potion."

"How do I know you'll get the right one?" Black could be accusing Severus of either cheating or carelessness; either way it was an insult. But two could play that game.

"You'll just have to trust me." Severus showed his teeth in a smile that really wasn't one. "Of the two of us, I'm the one who didn't play a prank that could have killed the other, after all."

The reminder shut Black up, and they each re-dressed in silence.

"Remember, you distract Slughorn. Better make it at the end of class on Wednesday. Then we'll meet here that night at eight o'clock," said Severus.

Black nodded. "I'll leave here first now: you wait." He slipped out of the room.

Severus was a little wary lest Black might be planning something right then, but when he left ten minutes later, there was no sign of the Gryffindor or any of his friends. Severus relaxed his grip on his wand.

He was slightly concerned about what the truth serum would reveal. While this had not been the best sexual encounter he had ever had, it had been better than he had expected, certainly in the top twenty-five percent, possibly the top ten percent. It would depend on just how much experience Black had previously had, and how satisfying that had been for him. Nothing to be done about it now.

Severus's theft of the truth serum went smoothly. As promised, Black held Slughorn's attention, and Severus was able to tip a few drops of serum into a vial he had brought for the purpose, under the guise of putting away some unused boomslang skin. He caught Black's eye on his way out and nodded to indicate his success.

"Two drops should do it," Black greeted him that evening, as soon as they had gone into the secret room. "I don't imagine either of us much wants to extend our truth-telling longer than necessary. Shall we agree that the only question to be asked is how good it was the other day?"

"Certainly." Severus drew out the tiny vial and a pair of spoons he'd take from the table at dinner. "Hold these and I'll pour."

Severus nodded. As soon as they had settled on the winner, he planned to go clean his teeth thoroughly, perhaps several times over. In the meantime, though... he looked around. Last time the room had provided pumpkin juice. He poured a glassful and drank, and Black did the same.

"Ready?" Severus asked when he had finished.

"Yes, I think it's working. Let's do this on an absolute scale, compared to the best we can imagine. Marks from one to ten. How good was it for you?"

Severus did not have to consciously think; the answer just popped out of his mouth. "An eight."

Black repeated, "Just an eight?" in disappointed tones.

"An eight. What about you, using the same scale?"

"A nine," Black admitted. "But I still say that what you did your tongue was unfair."

Severus shrugged and gave him a slight smirk. "And as I said, it was within the rules. If you'd thought of it, you could've done it too."

"I've never done it before," Black admitted. "But I'll try now... if you'll do it to me again too?"

Severus licked his lips. "First rimming, then a blow job?"

"Yeah." Black started pulling off his robes. Severus followed suit.

"I'll demonstrate first; pay attention to how it feels and think about what I must be doing. Then we can swap so you do me, and after that we can suck each other off," Severus suggested.

"Works for me." Black straddled his legs apart and bent over the edge of the mattress. Severus grabbed a pillow to cushion his knees and knelt behind him.

"Oh -- cleaning charm. I'll cast it on both of us."

That task complete, he used his hands to hold Black's arsecheeks apart and gazed with satisfaction at his rosy puckered hole, leaning in to tickle it with his tongue. Black gasped and groaned as Severus worked him open, plainly enjoying it even more than last time. When Severus realised that Black was frotting against the bed, he stopped. "Your turn."

Black grumbled a little, but swapped places. His tongue was hesitant at first. Severus guessed that he was apprehensive that there might be some unpleasant taste or smell, although perhaps it was simply the unfamiliarity of the act. Quite soon, however, he was licking and sucking almost greedily, his tongue spearing into Severus like a small but agile prick.

"Good, that's good, yeah," Severus encouraged him. More practice would improve his technique, but Black demonstrated a considerable degree of innate talent, and certainly a surprising amount of enthusiasm. He was nearly as good as Malfoy.

Much too soon, it seemed, Black pulled away. "Ready to suck?"

Severus shrugged. "Sure. Let's do it both at once." They stretched out on the bed, each facing the other's cock. Severus had only ever tried this position a few times; he didn't mind it, but found it awkward, not least because it was difficult to both enjoy being sucked off and do a good job of it oneself. He decided to focus on getting Black off first, so that he could enjoy his own orgasm without worrying that he might bite Black inadvertently. Not that Black didn't deserve it, for past behaviour, but Severus was finding he enjoyed their encounters enough to consider continuing them.

He rounded his mouth and let Black's prick slide between his lips, taking him nearly up to the hilt. It had required a good deal of practice to be able to do that without gagging. He paused, making sure his throat was relaxed, and felt the warm suction of Black's mouth on his own cock.

Moving his head, his tongue fluttering against Black's pulsating prick, Severus toyed with the loose skin of Black's bollocks, slipping a finger behind, into the crease, and titillating Black's still-damp arsehole. Black groaned, the vibration of his throat and mouth stimulating Severus's cock so that he had to pause and consciously hold back from coming. He pressed his fingertip deeper into Black's hole and sucked a little harder.

Cool air struck his wet prick as Black released him and emitted a strangled cry. His arsehole clenched tight around Severus's finger as his thick bitter spunk shot into Severus's throat. Severus gagged, trying to move back to breathe, but Black's thrusting hips kept his prick jammed deep into Severus's mouth. It was some seconds before Severus managed to draw away far enough to get sufficient breath and swallow.

"Sorry, sorry," said Black, and licked Severus's cock apologetically, his tongue teasing the slit before his lips parted to draw in Severus's full length. Severus could tell that Black had somehow picked up the trick of relaxing his throat. Knowing that, he didn't hesitate, but fucked Black's mouth with as much vigour as he could given the constraints of their relative positions. Orgasm seized him, leaving him feeling pleasantly wrung out in the aftermath. He lifted his head to look at Black and found the other boy gazing back at him.

"I think this should stay just between us... but I'd like to do it again," he said, the last lingering effects of the serum making him say more than he might have otherwise.

"I would, too. And I'm sorry about last year. You know, with Remus." Black's voice was reluctant, but Severus could have no doubt that he meant it, not under the serum's influence; certainly this was the best apology he could expect ever to get.

"Truce for now, then." Severus sat up. With his wand he cleaned himself up before putting his robes back on. "When you want me, you know where to find me." He tucked the vial with its remaining precious few drops of truth serum into his pocket, and left.